The Obama administration said Thursday it will allow many illegal immigrants facing deportation the chance to stay in the U.S. and apply for a work permit, while it focuses on removing those who pose a danger to public safety.

Officials announced plans to review 300,000 pending immigration cases and halt the deportations of people deemed to be a "low priority" — those who have lived in the U.S. for years without committing serious crimes.

The plans have given hope to scores of illegal immigrants on the brink of deportation but have roiled conservatives who charged the administration is trying to bypass Congress with administrative "amnesty."

The news follows months of intense pressure from immigrant advocates who have criticized the administration for deporting record-setting numbers of illegal immigrants while failing to deliver on comprehensive reform.

"This is the Barack Obama I have been waiting for and that Latino and immigrant voters helped put in office to fight for sensible immigration policies," said U.S. Rep. Luis V. Gutierrez, D-Ill. "Focusing scarce resources on deporting serious criminals, gang bangers and drug dealers and setting aside non-criminals with deep roots in the U.S. until Congress fixes our laws is the right thing to do."

Republican leaders and immigration-control advocates roundly criticized the plan on Thursday, saying it amounts to a sweeping overhaul of the nation's immigration policy without approval by Congress.

"The administration has again made clear its plan to grant backdoor amnesty to illegal immigrants," U.S. Rep. Lamar Smith, R-San Antonio, said in a statement. "The Obama administration should enforce immigration laws, not look for ways to ignore them."

Homeland Security Secretary Janet Napolitano outlined the plans briefly in a letter to assistant majority leader Sen. Dick Durbin, D-Illinois, and 21 other senators, writing that "it makes no sense to expend our enforcement resources on low-priority cases, such as individuals ... who were brought into this country as young children and know no other home."

Review process

White House and Department of Homeland Security officials on Thursday offered few specifics about how the review will be conducted. The officials, who spoke on condition of anonymity because the plan details had not been released, said a "working group" will be created to conduct the case-by-case review.

Officials said the reviewers will use a series of memos written by ICE Director John Morton that describe the agency's top priorities: deporting illegal immigrants with serious criminal records, repeat immigration violators and recent illegal entrants.

The working group will consider Morton's guidance on cases that merit special consideration, including young immigrants who have stayed in school and out of trouble, those with U.S. citizen relatives and people with health problems or other humanitarian issues.

Through the review process, the lowest-priority cases will be administratively closed, meaning the government will no longer be actively seeking to deport those immigrants, the officials said. People who have their cases closed will be eligible to apply for temporary work authorization, which will also be issued on a case-by-case basis, the officials said.

The review process affects only the roughly 300,000 people with pending immigration cases. It does not give the estimated 11 million illegal immigrants in the U.S. an opportunity to come forward and apply for work authorization, the officials said.

Prioritizing cases

Immigration agents and government attorneys also will be instructed to consider Morton's guidelines before initiating deportation proceedings, the officials said, which could significantly alter how the agency operates.

Immigration officials say they have to prioritize the deportations of the most serious offenders, given the government's limited resources. Morton estimated last summer that the agency has the resources to target about 400,000 illegal immigrants annually - roughly 4 percent of the illegal immigrant population. Last fiscal year, more than half of the illegal immigrants for deportation had criminal records, according to ICE.

While immigrant advocates heralded the review as a sound policy decision and a step forward, union officials said it will stop field agents from enforcing the law.

"Congress has good laws on the books," said Tre Rebstock, president of the local ICE union. "The problem is that this administration doesn't like them. This administration is trying to enforce the laws it thinks we should have ... without Congress' consent."